Laser plastic welding has established itself as a particularly precise and hygienic process in addition to other joining methods and already offers a variety of methods for monitoring and assuring quality during the process (Our partner for testing and measuring technology: Intego GmbH).

In laser plastic welding (also called laser transmission welding), an upper part that is transparent to the laser wavelength is combined with an absorbing lower part. The laser beam is focused through the laser-transparent molded part onto the absorbent joining partner, causing it to melt on the surface. By introducing a joining pressure on the component halves to be welded, a material-to-material bond is created.

Depending on the relative movement between the laser beam and the joining partner and the type of energy input, laser welding of plastics is divided into different process variants. On these pages, we present the most common variants. A variant that is used very often is contour welding.

In contour welding, the weld seam is traced once or several times with the laser. The plastic is only melted at the point of direct laser impact and then immediately solidifies again, so that there is no melt expulsion, as shown in the animation above. The process can also be used for components with large dimensions.

The main applications for laser welding of plastics are in the automotive, medical technology, pharmaceutical and consumer goods sectors.